CHAPTER 7—Skiplane Operations


  • Glaciers—Sloping snow or ice packs.
  • Frozen Lakes—Frozen bodies of water with or without snow cover.
  • Tundra—A large area of grass clumps supporting snow cover.


Before departing on any trip, it is important to do proper preflight planning. A good preflight should include a review of the proposed route as well as possible alternate routes; terrain; local, en route, and destination weather; fuel requirements; facilities available at the destination; weight and balance; and takeoff and landing distance requirements.

Obtain a complete weather briefing for each leg, and file a flight plan with appropriate remarks. For local flights, always inform someone at home of the area of operation and the expected time of return if a flight plan is not filed.

Include good Aeronautical Decision Making (ADM) procedures, such as running a personal minimums checklist, and think PAVE (Pilot, Aircraft, Environment, and External Pressures) during the preflight phase.

Cold weather is implicit in flying a skiplane, so preflight planning must also include preparations for possible contingencies unique to cold weather operations. This is especially important for flights in bush country, where facilities are scarce and emergency assistance may be limited or nonexistent.

Evaluate all passengers’ clothing for suitability in the conditions expected. Consider the passenger when making this evaluation. Children and older people need more protection from the environment than a middleaged person in good health. Every occupant should be dressed for a long walk, including adequate boots or rubber-bottomed shoes and an arctic parka. Sunglasses are highly recommended, even on cloudy days. Pilots can be blinded by the brightness of the snow, and glare can destroy depth perception.

Survival equipment is required by some states and countries, and many areas require specific items for even the shortest local flights. The requirements usually vary between winter and summer months. Be sure to check the current requirements for the particular jurisdiction. Beyond the minimum requirements, use good judgment to select and carry any other equipment that could help occupants survive an unplanned stay in the specific terrain and environmental conditions along the route of flight. Always consider means of providing warmth, shelter, water, and food; methods of attracting attention and signaling for help in both daylight and darkness; and treatment of injuries. Obtain appropriate survival training and know how to make effective use of the equipment. Whether the cause is a forced landing or an engine that fails to restart after landing at a remote location, the survival gear and clothing should keep the pilot and passengers alive until help arrives.

When planning for an overnight stay away from an airport, or if the skiplane is routinely parked outside, other items may be added to the equipment carried on the skiplane. These might include portable tiedowns, a flashlight, a shovel, and a broom. Wing and fuselage covers can prevent the buildup of frost and snow, simplifying the preflight. In temperatures below 0° F, an engine cover and a catalytic heater may be necessary to preheat the engine compartment. If the pilot carries appropriate hand tools and a bucket, the crankcase oil can be drained from the engine and kept indoors. It may also be helpful to remove the battery and keep it in a warmer location. Many pilots carry burlap sacks, plastic garbage bags, or wooden slats to place under the skis to prevent them from freezing to the surface. Some carry a can of non-stick cooking spray to use on the bottom of the ski to avoid sticking or freezing to the surface. Depending on the needs of the skiplane, it may be necessary to carry extra engine oil, hydraulic fluid, or deicer fluid. Markers such as red rags, colored flags, or glow sticks may come in handy, as well as 50 feet of nylon rope, and an ice pick or ice drill. Select equipment according to the situation, and know how to use it.

If a skiplane has been sitting outside overnight, the most important preflight issues are to ensure that the airframe is free of snow, ice, and frost and that the skis are not frozen to the ground. Often, while sitting on the ground, precipitation may fall and cover the skiplane. Temperatures on the ground may be slightly colder than in the air from which the precipitation falls. When liquid precipitation contacts the colder aircraft structure, it can freeze into a coating of clear ice, which must be removed completely before flight. Wing and tail surfaces must be completely frost free. Any frost, ice, or snow destroys lift and also can cause aileron or elevator flutter. Aerodynamic flutter is extremely dangerous and can cause loss of control or structural failure.

The preflight inspection consists of the standard aircraft inspection and includes additional items associated with the skis. The AFM or POH contains the appropriate supplements and additional inspection criteria. Typical inspection criteria include:

  • Skis—Examine the skis for damage, delamination, sheathing security, and overall condition.
  • Hardware—Inspect the condition and security of the clamping bolts, cotter keys, diaper pins, limiting cables, and bungees. Be sure cables and bungees are adjusted properly.
  • Retracting Mechanism—(if equipped)—Check the hydraulic fluid level and examine the hydraulic lines for leaks. Inspect all cables for fraying and check cable ends for security. Do not cycle the retracting mechanism while on the ground.
  • Ski Freedom—Be sure the skis are free to move and are not frozen to the surface. If the ambient temperature approaches the melting point, the skis can be freed easily. Gentle swinging of the tail at the rear fuselage, or rocking the airplane at the struts may free the skis. If this does not work, dig the skis out.
  • Tire Pressure—Check the tire pressure when using skis that depend on the tires for shock absorption, as well as for combination skis. This is especially important if moving a skiplane from a warm hangar to cold temperatures outdoors, as tires typically lose one pound of pressure for every ten-degree drop in ambient temperature.
  • Tailwheel—Check the tailwheel spring and tail ski for security, cracks, and signs of failure. Without a tail ski, the entire tailwheel and rudder assembly can be easily damaged.
  • Fuel Sump—During fuel sump checks, sometimes moisture can freeze a drain valve open, allowing fuel to continue to drain. Ice inside the fuel tank could break loose in flight and block fuel lines causing fuel starvation. If the manufacturer recommends the use of anti-icing additives for the fuel system during cold weather operations, follow the ratio and mixing instructions exactly.
  • Survival Equipment—Check that all required survival equipment is on board and in good condition.
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